This invention relates generally to high-voltage electrical apparatus and more particularly to a high-voltage, compressed gas-insulated transmission line having a corrugated outer housing.
Compressed gas-insulated transmission lines are being increasingly utilized to transmit large magnitudes of electrical energy. Typical gas-insulated transmission lines include a cylindrical, rigid outer sheath, or outer housing, typically at ground potential, and a high-voltage inner conductor disposed within the outer sheath. An insulating gas, such as sulfur hexafluoride, is utilized inside the outer sheath to electrically insulate the inner conductor from the outer sheath. Insulating spacers are utilized at spaced intervals along the length of the transmission line to insulatably support the inner conductor within the outer sheath.
One disadvantage with the typical gas-insulated transmission line is that the lines themselves are rigid; they cannot be significantly bent or turned to accommodate changes in direction or to avoid unforeseen obstacles within their path. All changes of direction in a transmission line must therefore typically be accomplished through the use of elbows or junction boxes. To overcome this drawback, a new type of gas-insulated transmission line is being investigated. The new type of gas-insulated transmission line utilizes a corrugated outer sheath and a flexible inner conductor to provide flexibility in the transmission line. This flexibility can then be utilized to facilitate changes of direction.
Because both the typical transmission line and the new flexible transmission line are typically fabricated of a plurality of transmission line sections, with lengths typically of the order of 60 feet each, joining means must be utilized for sealingly and fixedly joining the various transmission line sections together. This joining means should be low cost and field-installable, be able to withstand the mechanical forces exerted upon it, and preferably should allow no contamination to enter the interior of the outer housing during the joining process.